System of electrical distribution



No. 625,8l6. Patented May 30, I899.

E. THOMSON.

SYSTEM OF ELECTRICAL DISTRIBUTION.

(Application fllod Sept. 10, 1897.) -(IIo Model.) 2 Sheets-Sheet l.

K WITNEEIEIEEJ- .3 $4|NVENTEIFL 'No. 625,8I6. Patented May 30, I899.

E. THOMSON. SYSTEM OF ELECTRICAL DISTRIBUTION.

(Application fllad Sept. 10, 1897.)

2 Sheets-Shoot 2.

(lIo Modal.)

FE-Z.

AAAAAAMAA s O O O O |Nv|= TEIH UNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF SIVAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO THE I GENERAL ELECTRIC COMPANY, OF NEWV YORK.

SYSTEM OF ELECTRICAL DISTRIBUTION.

SPECIFICATION forming part of Letters Patent No. 625,816, dated May 30, 1899.

Application filed September 10, 1897- Serial No. 651,212. (No model.)

To 61/ whom it may concern:

Be it known that I, ELIHU THOMSON, a citizen of the United States, residing at Swampscott, in the county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Systems of Electrical Distribution, (Case No. 616,) of which the following is a specification.

The present invention relates to the regulation of an electric current in systems of distribution in which constant-potential alternating currents are employed with translating devices requiring constant current.

It has for its object to preserve in a large degree the advantages attendant upon both systems and to overcome some of the defects of each. For example, it permits me to employ the small conductors suitable for hightension currents, with consequent saving in copper. At the same time the difference of potential between'the mains or between the line and ground is approximated. to that of the constant-potential system. By a suitable application of the principles of this invention the difference of potential referred to may, indeed, be reduced to any desired degree, limited only by consideration of economy. I also combine the regulation of the two systems in such manner that although the source of current may be one designed for constant-potential the effect in the regulated circuit is that of constant current.

The accompanying drawings are diagrams illustrating the principles of my invention.

Figure 1 is one form, and Fig. 2 a modification.

In Fig. 1, Z Z represent the sides of the con stant-potential alternating-current system, feeding any kind of translating devices. A branch starting at a passes through the secondary S of a transformer T, which is of the constant-current type, the primary P of which is connected in shunt to the mains Z Z In circuit with the secondary S is a series of translating devices, such as lamps L, which may be followed by a coil S at second set or series of translating devices L, the. This constitutes a series system, with a distribu tion of lights and secondary coils of transformers in series. Taken from the mains Z Z at some convenient point are submains b b,

- lamps in series.

from which may be again branched wires 5 b feeding a primary coil P of which S is the secondary in a transformer. Suitable fuses F F are provided in the branch wires wherever necessary. In like manner branches feed P, the secondary corresponding to which is S in the transformer shown, and P corresponds in the same manner to S The transformers P S to P S may be of constant-potential type.

The action of the system is as follows: It may be desired to work a large number of The potential of the system Z Z may be adapted to take care of such a load; but at the same time it may be desirable to so divide up the potential as not to have it at any point in the system so high as would be required to work all the lamps in series. In this case the primaries P P, 850., being supplied by the constant-potential lines Z Z set up currents at any desired ratio of transformation of potential in S S 850., which, being in the same direction as the impressed potential from the lines Z Z give, as it were, a tandem generation of potentials, with the load between these generators or secondaries S to S The total effective potential is thus very much increased on the system over what it would be if the potential on the lines Z Z were alone impressed on the series system. At the same time at no point in the system or the load can there be any greater potential difference between line and earth or between the two lines than the highest potential of any secondary S 850., or the potential of the lines Z P.

The regulation of the current to constancy in such a system where minor variations of load occur is readily accomplished by the transformer T, with its primary and second- .ary related as in a constant-current transtoo ' former .T has widerange and tends to pre secondary.

T the exact amountof work done by the coil.

S may be-followed, and the condition of the load in relation to the impressed potentials noted. Should it be desired to cut out any set of lamps, as L, without disturbing the ac-' tion of the system, this can be done by shortcirc uiting both the secondarys and the lam ps L by a suitable switch V, which switch is'con-w.

structed to open at the same time the branch circuit through the coil P or the primary corresponding to the shunted'secondary S Thisleaves the system in balance, as before, witha portion of the load out out.

If it be desired to operate the system inde-'' pendent of any direct connectionsuch as ab, taken from the mains Z P-the connections a bwould be. severed and connected across,

asshown by the dotted line. In such case there would of course be a diminution in the load. carried, since the effective potential is decreased by an amount equal tov the diiference of potential between Z P; but the systemv so far asthe coils S to S ortheir corresponding primaries areconcerned would remain the The system permits of otherinodifications I The feature of the-system just described, which consists which are exhibited in Fig. 2.

in the. employment of a single constant-curf renttransformer to bring the current to con-I stancy and regulate for variations from con-I stancy in the system, but which is not in itself aconstant-current system so far as the action of other devices are concerned,is em-. ployed in a different way in this figure; but

inithis instance there is no such advantagei attained as the one which results from the connection of the electromotive-force sources in series with the portions of the load, whereby a very highpctential system becomes safe on account of the subdivision of the potential.

In.Fig. 2 the mains Z Z are branched at a I) through a series of primary coils P to'P which. may be of the constant-potential type.v

This line is carried through the secondary of a constant-current transformer T, the. primary of which is represented at P. This transs vent any departure from constancy of the other coils with which it is in series.

maries P ,&c.,have correspondin gsecondaries S to S the potentials in which may be greater or less than that between the terminals of any primary. The load upon these secondaries wouldbe a certain number of translating devices in series generally or a certain number in The pri-1 correspond to a number consuming one thousand volts. Any other ratio might exist in the other coils, provided the work of each is proportioned properly, or they may all be of standard potential in the system. The cutting out of a coil P by shunting can be effected'with'the'extinguishing of the lights corresponding to it, as those at L, while the constant-current transformer T makes up the difference and. keeps the current constant for the rest of thecircuit, notwithstanding the constant potential between Z 1 An accidental opening of the circuit of-the line L'with its lights would eauseia very high potential'at the terminals of S or P and interfere with the effectiveness ofthe system; but this can be provided for readily by, placinga film cut-out to be puncturedby this high potential, which film cut-out may-span the:terminals.ofthe secondary S or, as in the case of-the-coil P it may span the terminals of the will, as atF. In case of rupture'of vthe cor-responding secondary circuit the film cut-out-will be-punctured ifproperly proportioned and shunt the system, thus permitting the working of .the'remaining load, which wouldbe regulated as to its normal operation by the constant-current transformer.

What l clainrasnew, and desire tosecure by Letters Patentofthe-United States, is

1. Ina system of distribution, the combination-with constant-potential mains, of a circuitacross them containing constant-potential transformer-windings connected in series, anda regulator in the series for maintaining the current therein constant.

2. Ina system of distribution, the combination with constant potential mains, of constant-potential transformer-windings connected in series across the mains, and'a constant-current secondary connected in'the-series circuit.

3. In a system of distribution, the combination with constant-potential mains, of a circuit across the mains containing a number of transformer-secondaries.of the constant-potentialtype connected in series, with translating devices between them, and a regulating device connected in the series circuit and tendingto maintain constant current therein.

4. In a system of distribution, the combination with constant-potential mains, of a circuit-across said mains containin g transformerwindings normallysupplying energy to translating devices in series therewith, and means for maintainingaconstant current in said circuit.

5. In a system of distribution, a circuit containing a plurality of translating devices normally supplied with energy from a plurality of transformer-windings in series and means for maintaining a constant current in said circuit.

6. In a system of distribution the combination of groups of translating devices and secondary windings alternately connected in series, and a primary circuit for supplying energy to all of said secondary windings.

7. In a system of distribution, the combination of translating devices in series, transformer-secondaries in series with each other and with said devices and normally supplying energy thereto and means for supplying energy to said secondaries.

S. In a system of distribution, the combination of translating devices, transformers of the constant-current and of the constant-potential type having their secondaries in series with said translating devices, and means for supplying energy to said transformers.

9. In a system of distribution the combination of secondary windings in series, a primary circuit supplying energy for allot said secondary windings and translating devices arranged in series and interposed between said secondary windings.

10. In a system of distribution, the combi nation of secondary windings in series, a primary circuit supplying energy for said secondary windings, translating devices in the circuit between said windings but not in shunt to one of the windings, and means for regulating the amount of energy consumed by said translating devices.

11. In a system of distribution, the combination of a plurality of transformer-secondaries connected in series across constant-potential mains and means for maintaining a constant current in the circuit including said secondaries.

12. In a system of distribution, the combination of secondary windings in series, a primary circuit supplying energy for said secondary windings, translating devices in the circuit between said windings and means for simultaneously cutting out of circuit a secondary winding and translating devices.

13. In a system of distribution, a circuit containing translating devices in series with a plurality of sources of electromotive force and means for simultaneously eliminating translating devices and one or more of said sources of electromotive force from the circuit.

14. In a system of distribution, the combination with constant-potential mains, of constant-potential transformers havingtheir secondaries connected in series, with translating devices connected in series between them and requiring approximately constant current for their proper operation, the primaries of the constant potential transformers being in shunt across the mains, and a constant-current transformer the secondary of which is connected in series with the other secondaries and the translating devices, and the primary of which is connected across the mains.

15. In a system of distributiomthe combination of a plurality of transformers with their secondaries connected in series with each other and with a plurality of translating devices to which energy is normally supplied through the medium of said transformers, and means external to said transformers for regulating the current in said secondaries.

16. The combination with a series system of translating devices of a plurality of transformer-secondaries arranged in series therein and all of said secondaries normally furnishing energy thereto.

In witness whereof I have hereunto set my hand this 4th day of September, 1897.

ELIHU THOMSON.

Witnesses:

JOHN W. GIBBONEY, HENRY O. WESTENDARP. 

